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1// SPDX-License-Identifier: GPL-2.02/*3 * A driver for the RTC embedded in the Cirrus Logic EP93XX processors4 * Copyright (c) 2006 Tower Technologies5 *6 * Author: Alessandro Zummo <a.zummo@towertech.it>7 */8 9#include <linux/module.h>10#include <linux/mod_devicetable.h>11#include <linux/rtc.h>12#include <linux/platform_device.h>13#include <linux/io.h>14#include <linux/gfp.h>15 16#define EP93XX_RTC_DATA 0x00017#define EP93XX_RTC_MATCH 0x00418#define EP93XX_RTC_STATUS 0x00819#define EP93XX_RTC_STATUS_INTR BIT(0)20#define EP93XX_RTC_LOAD 0x00C21#define EP93XX_RTC_CONTROL 0x01022#define EP93XX_RTC_CONTROL_MIE BIT(0)23#define EP93XX_RTC_SWCOMP 0x10824#define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f000025#define EP93XX_RTC_SWCOMP_DEL_SHIFT 1626#define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff27#define EP93XX_RTC_SWCOMP_INT_SHIFT 028 29struct ep93xx_rtc {30 void __iomem *mmio_base;31 struct rtc_device *rtc;32};33 34static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,35 unsigned short *delete)36{37 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);38 unsigned long comp;39 40 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);41 42 if (preload)43 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)44 >> EP93XX_RTC_SWCOMP_INT_SHIFT;45 46 if (delete)47 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)48 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;49 50 return 0;51}52 53static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)54{55 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);56 unsigned long time;57 58 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);59 60 rtc_time64_to_tm(time, tm);61 return 0;62}63 64static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)65{66 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);67 unsigned long secs = rtc_tm_to_time64(tm);68 69 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);70 return 0;71}72 73static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)74{75 unsigned short preload, delete;76 77 ep93xx_rtc_get_swcomp(dev, &preload, &delete);78 79 seq_printf(seq, "preload\t\t: %d\n", preload);80 seq_printf(seq, "delete\t\t: %d\n", delete);81 82 return 0;83}84 85static const struct rtc_class_ops ep93xx_rtc_ops = {86 .read_time = ep93xx_rtc_read_time,87 .set_time = ep93xx_rtc_set_time,88 .proc = ep93xx_rtc_proc,89};90 91static ssize_t comp_preload_show(struct device *dev,92 struct device_attribute *attr, char *buf)93{94 unsigned short preload;95 96 ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL);97 98 return sprintf(buf, "%d\n", preload);99}100static DEVICE_ATTR_RO(comp_preload);101 102static ssize_t comp_delete_show(struct device *dev,103 struct device_attribute *attr, char *buf)104{105 unsigned short delete;106 107 ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete);108 109 return sprintf(buf, "%d\n", delete);110}111static DEVICE_ATTR_RO(comp_delete);112 113static struct attribute *ep93xx_rtc_attrs[] = {114 &dev_attr_comp_preload.attr,115 &dev_attr_comp_delete.attr,116 NULL117};118 119static const struct attribute_group ep93xx_rtc_sysfs_files = {120 .attrs = ep93xx_rtc_attrs,121};122 123static int ep93xx_rtc_probe(struct platform_device *pdev)124{125 struct ep93xx_rtc *ep93xx_rtc;126 int err;127 128 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);129 if (!ep93xx_rtc)130 return -ENOMEM;131 132 ep93xx_rtc->mmio_base = devm_platform_ioremap_resource(pdev, 0);133 if (IS_ERR(ep93xx_rtc->mmio_base))134 return PTR_ERR(ep93xx_rtc->mmio_base);135 136 platform_set_drvdata(pdev, ep93xx_rtc);137 138 ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);139 if (IS_ERR(ep93xx_rtc->rtc))140 return PTR_ERR(ep93xx_rtc->rtc);141 142 ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops;143 ep93xx_rtc->rtc->range_max = U32_MAX;144 145 err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files);146 if (err)147 return err;148 149 return devm_rtc_register_device(ep93xx_rtc->rtc);150}151 152static const struct of_device_id ep93xx_rtc_of_ids[] = {153 { .compatible = "cirrus,ep9301-rtc" },154 { /* sentinel */ }155};156MODULE_DEVICE_TABLE(of, ep93xx_rtc_of_ids);157 158static struct platform_driver ep93xx_rtc_driver = {159 .driver = {160 .name = "ep93xx-rtc",161 .of_match_table = ep93xx_rtc_of_ids,162 },163 .probe = ep93xx_rtc_probe,164};165 166module_platform_driver(ep93xx_rtc_driver);167 168MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");169MODULE_DESCRIPTION("EP93XX RTC driver");170MODULE_LICENSE("GPL");171MODULE_ALIAS("platform:ep93xx-rtc");172